Lithographic plate developing apparatus

ABSTRACT

Developing of lithographic plates is accomplished on apparatus providing for applying the various chemicals used in the developing process by moveable applicators and spreading contact members. The applicators and spreading contact members move cyclically back and forth over the surface of the lithographic plate and are selectively operable to apply and spread any given chemical or water to the surface during any given cycle of the applicator and contact member assembly.

limited States Meat 9] Haracz 1 1 LITHOGRAPHIC PLATE DEVELOPING APPARATUS [76] lnventor: Edward F. ll-laracz, 4-12 Orono Street, Clifton, NJ. 07013 22 Filed: Feb. 18, 1972 21 Appl. No.: 227,533

[52] US. Cl ..95/89 R, 118/113, 118/120 [51] Int. Cl. ..G03d 5/04 [58] Field of Search ..95/89 R, 94 R, 99; 118/111,

[56] References Cited UNITED STATES PATENTS 820,666 5/1906 Newell et al 1 18/120 3,528,358 9/1970 Pickard ..95/89 R 3,593,641 7/1971 Adams et al. ..95/89 R 3,608,464 9/1971 Harrell et al ..95/89 R [451 March 6, 1973 ll/l97l 8/1972 Bogue ..95/89 R Parker et a1. ..95/89 R Primary Examiner-Samuel S. Matthews Assistant Examiner-Fred L. Braun Att0rneyThomas Cifelli, Jr. et a1.

[57] ABSTRACT Developing of lithographic plates is accomplished on apparatus providing for applying the various chemicals used in the developing process by moveable applicators and spreading contact members. The applicators and spreading contact members move cyclically back and forth over the surface of the lithographic plate and are selectively operable to apply and spread any given chemical or water to the surface during any given cycle of the applicator and contact member assembly.

9 Claims, 8 Drawing Figures PATENTEU R 61 73 sum 1 OF 4 FIG. 2

FIG.1

PATEHTEEM a 375 SHEET 2 0F 4 LITHOGRAIHIC PLATE DEVELOPING APPARATUS BACKGROUND OF THE INVENTION This invention relates to lithography and more particularly is directed to an improved lithographic plate developing apparatus.

Lithographic plate developing machines used heretofore provide for mounting the plate to be developed in a horizontal position over which the chemicals used in the developing and coating processes are sequentially floated and thence removed by manually wiping or scraping. By necessity such machines have occupied relatively large areas of space in addition to being costly to make, cumbersome and relatively messy in operation and requiring more manual operation than is desirable.

Thus, it is an object of the present invention to provide a greatly simplified lithographic plate developing apparatus.

It is another object of the present invention in its preferred form to provide a lithographic plate developing machine which is relatively small and occupies a small horizontal area.

It is yet another object of the present invention to provide a lithographic plate developing apparatus which is fully automated thus requiring a minimal of manual operation.

It is still another object of the present invention to provide lithographic plate developing apparatus in which the chemicals used in the developing and coating of the lithographic plate are readily and easily applied and similarly are readily and easily spread over the surface of the lithographic plate and removed therefrom with a minimum of messy procedures.

SUMMARY OF THE INVENTION By the present invention, a lithographic plate developing machine is provided which has a horizontal base with a front plate member mounted thereon. Holding means are provided for temporarily but securely mounting a lithographic plate to be developed on the front plate member while developing means extending transversely across the front plate member are adapted for longitudinal cyclic movement back and forth over the front plate member in a plane parallel thereto. The developing means includes a plurality of applicators for sequentially applying to the lithographic plate to be developed, the various chemicals and liquids used in the developing process during subsequent cyclic motions of the developing means and also a plurality of contact means for evenly spreading the chemicals and liquids over the surface of the lithographic plate being developed. The plurality of contact means are selectively indexable to provide predetermined contact with the lithographic plate by only one of the contact means during any given cycle of the developing means. Further, oscillating means are provided for imparting transverse back and forth motion to the contact means.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, advantages an features of the lithographic plate developing apparatus of the present invention will become even more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like numerals refer to like parts:

FIG. 1 is a front elevational view of the preferred embodiment of the lithographic plate developing apparatus of the present invention;

FIG. 2 is a side elevational view of the apparatus shown in FIG. 1 with some parts removed for clarity;

FIG. 3 is a plan, cross-sectional view through the developing cylinder used in the lithographic plate developing apparatus of the present invention;

FIG. 4 is an end elevational view of the developing cylinder shown in FIG. 3;

FIG. 5 is a front elevational view of the developing cylinder shown in FIG. 3 but which in addition shows the oscillating mechanism and indexing mechanism employed therewith;

FIG. 6 is a schematic perspective view of the developing cylinder shown in FIG. 3 and in addition showing the spray pipes and and ancillary equipment used to apply the chemicals in the developing and coating process; a

FIG. 7 is a top plan view of another embodiment of the lithographic plate developing apparatus of the present invention; and

FIG. 8 is a side elevational view of the embodiment of the present invention shown in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION Referring first particularly to FIG. 1, there is shown a preferred embodiment of the lithographic plate developing apparatus generally designated by the numeral 10. The apparatus 10 includes a rectangular base member 12 which supports a pair of opposed vertical side frame members 14 and 16. Traversing the space between side frame members 14 and 16 and mounted on the front edges thereof is a front plate member 18 which is provided in its central portion with an area of perforations 20 overlying a vacuum chamber 22 mounted on the under surface of the front plate member 18. In this preferred embodiment, it is seen that the front plate member 18 is inclined upwardly at an angle with respect to the rectangular base 12 (FIG. 2).

Positioned transversely over the outer surface of front plate member 18 is a spray pipe 24 developing cylinder 26 assembly (explained in greater detail hereinafter) which is adapted to move up and down over the front surface of front plate 18 in a plane parallel thereto by means of rotatable ball screws 28 and 30 which support the spray pipe-developing cylinder subframe members 32 and 34 threadably mounted thereon. Ball screws 28 and 30 are suitably journaled for rotation adjacent each end and are rotated through a main drive train 35 powered by a reversing motor (not shown) housed within the base 12. By such reversible rotation of ball screws 28 and 30, subframe members 32 and 34 and the spray pipe 24 developing cylinder 26 assembly carried thereby are driven cyclically up and down over the surface of a lithographic plate (not shown) mounted on the front surface of the front plate member 18. The distance the spray pipedeveloping cylinder assembly moves is, of course, dependent upon the size of the lithographic plate to be developed and can be pre-selected, by way of example,

by suitably placed limiting switches (not shown) which reverse the rotational direction of the reversing motor at the desired top and bottom ends of the developing cycle.

Referring now more particularly to FIGS. 3, 4 and 5, the developing cylinder 26 is seen to consist of four transversely extending contact segments 36 circumferentially and radially spaced around three supporting plates 38 spaced longitudinally and fixed on a central rotatable shaft 40. Fixed collar bushings 42 surround the center shaft 40 and maintain the axial spacing of the support plates 38 on the shaft 40. Each of the contact segments 36 is provided on its outer surface with a layer 43 of soft material such as felt, soft sponge, cloth, rubber, plastic, and the like.

The axle shaft 40 of the developing cylinder 26 is suitably journaled for both rotation and axial sliding motion near each end in subframe members 32 and 34. At one end of the axle shaft 40, a sprocket wheel 44 is mounted for rotation therewith while at the same time permitting axial movement of the shaft 40 with respect thereto. This can be accomplished, for example, by providing longitudinal splines (not shown) on the shaft 40 which mate in sliding engagement with longitudinal grooves provided on the inner surface of the hub 45 of the sprocket wheel 44. These longitudinal splines on the shaft 40 would also similarly mate in sliding engagement with the inner race of the bearings journaled in the subframe members 32 and 34 to permit axial sliding motion of the shaft 40 relative to the subframe members 32 and 34.

At the other end of the shaft 40 is a bearing member 46, fixed against axial motion with respect to the shaft 40, but permitting the shaft 40 to rotate relative thereto.

Adapted to rotate the shaft 40 and thereby the developing cylinder 26 is an indexing motor 48 which drives the sprocket 44 through a predetermined angle of rotation. In the embodiment shown, where four contact members 36 are employed, the predetermined angle of rotation will normally be selected at 90. However, it will be understood that more or even fewer than fourcontact segments 36 could be employed depending upon the number of coating or washing operations that are desired in the lithographic developing process and in such instances, the indexing motor 48 will be set to rotate the sprocket 44 through the required angle to place the desired contact segment 36 in contact with the lithographic plate being developed (explained more fully hereinafter).

To provide axial, oscillating motion to the shaft 40 and thereby also to the developing cylinder 26, a cam linkage 50 is provided between the bearing collar 46 on the shaft 40 and a motor 52 driven at a relatively constant velocity. This axial, oscillating motion imparted to the contact segments 26 assures even spreading of the various chemicals employed in the lithographic developingprocess.

Mounted above the developing cylinder 26 (FIGS. 1 and 6) and fixed for cyclic movement therewith by a pairof upright supports 54 (one shown), are a series of transverse spray pipes 24 provided with a series of Iongitudinally spaced nozzle openings 56' directed toward the front, plate member 18. In the embodiment shown, three separate spray pipe applicators 24 are employed but fewer or more can be used depending upon the number of various chemicals that are desired in any given lithographic plate developing process. However, for the purpose of illustration only, a two chemical process, developer and coating gum, is described herein.

Supported by the vertical side frame members 14 and 16 (FIG. 1) are containers 56 and 58, one of which contains the lithographic developer and the other a coating gum. The particular developers and coating gums used are well known in the art and any of the many developers and coatings can be selected.

From the containers 56 and 58, fluid lines 60 and 62 lead into pumps 64 and 66 (FIG. 6). From the outlet end of the pumps 64 and 66, through solenoid valves 68 and 70, are flexible hoses 72 and 74 leading to two of the spray pipe applicators 24. The third spray pipe applicator in the embodiment shown is connected, also through a solenoid valve 76 by way of flexible hose 78, to a water supply to provide wash water between or subsequent to application of the developers or coating gums. The predetermined opening or closing of solenoid valves 68, and 76 is controlled by means of a timer 80 which, in a manner explained more fully hereinafter, is set according to each cyclic movement of the spray pipe applicator 24 developing cylinder 26 assembly over the lithographic plate being developed.

Also controlled by the timer 80 are the vacuum pump 82 and the drier fan 84 which are employed to hold the lithographic plate to the front plate member 18 and to dry the developer and coating chemicals between or after the application thereof by the spray pipe applicator 24, respectively. While not specifically shown, the drier 84 would also be adapted to move cyclically with the spray pipe applicator 24 developer cylinder 26 assembly and, through the timer 80, be operable between applications of either the developer or the coating gum subsequent to sequential cycles of the spray pipe applicator developer cylinder assembly.

While the foregoing, in general, has described the preferred embodiment of the lithographic plate developing apparatus 10 as a unit with a single lithographic plate developing station, reference to FIG. 2 shows the preferred embodiment based on FIG. 1 where two developing stations can be provided in a single unit on the base 12. In this instance, the front plate members 18 are opposed and inclined upwardly at an angle from the base toward each other at the top of the unit, with the spray pipe applicator (not shown) developer roll 26 assembly and its attendant vacuum chambers 22, supporting and driving structures duplicated on each side. Also, the developer and coating containers 56 and 58 along with their ancillary piping, pumps, solenoid valves, timers, vacuum pumps, water supply, and drying fans are duplicated for the opposed plate developer stations.

Now, in the operation of the preferred embodiment described hereinabove, an exposed lithographic plate (not shown) is placed on the surface of the front plate member 18 and the vacuum pump 82 is activated by the timer 80 to evacuate the air from the vacuum chamber 22 thereby holding the plate temporarily but securely to the front plate member 18. The reversing motor (not shown) driving the main drive train 35 is activated to turn the ball screws 26 and 36 while at the same time, the pre-set timer litl is operative to open the solenoid valve 68 to permit flow of the developer from the container 56 through one of the spray pipe applicators 24. Also, at this time, indexing motor 4% has rotated the developing cylinder 26 through an appropriate angle so that one of the contact segments 36 is in contact with the lithographic plate being developed, with the oscillating motor 52 being activated to oscillate through the cam mechanism 50 the developing cylinder 26 in a direction transversely of the lithographic plate.

For the purpose of the above description of the operation of the preferred apparatus of the present invention, the initial start-up of the apparatus will assume a beginning positioning of the spray pipe applicator 24 developing cylinder 26 assembly at its upper most level over the lithographing plate being developed. From this position, the spray pipe 24 developing cylinder 26 assembly moves downwardly by the rotation of ball screws 28 and 30, at the same time applying and spreading the developer solution from the container 56, until it reaches the preselected lower most desired position over the lithographic plate being developed. At this point, a micro switch or timing mechanism is tripped or is operative to reverse the reversing driving motor thus rotating the ball screws 28 and 30 in the opposite direction. Also, the timer 80 is now operative to close the solenoid valve 68 to cut off the flow of developer to the lithographic plate.

; With the ball screws 28 and 30 now rotating in the opposite direction, the spray pipe 24 developing cylinder 26 assembly moves upwardly until it reaches its uppermost level or starting position over the lithographic plate where again a micro switch or timing mechanism is tripped or is operative to reverse the reversing driving motor to start the next cyclic travel of the spray pipe applicator 24 developing cylinder assembly over the lithographic plate.

This second cycle finds the timer 86 pre-set to open the solenoid valve 76 thus supplying wash water to the lithographic plate to wash away any excess developer therefrom. Also, the indexing motor 48 has been activated to rotate the developing cylinder 26 through the desired angle to place the next adjacent contact segment 36 against the lithographic plate with the oscillating motor 52 still operative to oscillate the developing cylinder 26 and its contact member 36 transversely of the lithographic plate thus assuring even spreading and complete washing with the wash water.

Again, when the spray pipe applicator 24 developing cylinder 26 assembly reaches its lowermost desired position over the lithographic plate, the timer 80 closes solenoid valve 76 shutting off the wash water supply, the reversing motor is again reversed and the spray pipe applicator 24 developing cylinder 26 assembly is returned to the top of its cyclic travel.

The third and fourth cycles, completing the lithographic plate developing process, proceed in the same manner as described above with respect to the first and second cycles. During the third cycle, however, the timer 80 opens the solenoid valve 70 to apply the coating gum to the lithographic plate from the container 58 and during the fourth cycle the timer 80 is operative to turn on the drying fan 84 to dry the developed lithographic plate with warm air.

After completion of the developing process, the timer 8(1) shuts off all mechanisms and the vacuum pump is de-energized to release the developed lithographic plate for removal from the front plate member because of the verticalized positioning of front plate member lid in the preferred embodiment of the present invention, drains by gravity into a drain trough 86 (FIG. 2) which is thence drained by sewer. This is particularly advantageous as it obviates the necessity for manual operations to clean off the excess chemicals that remain on the surface of prior art lithographic developing machines which position the lithographic plate being developed in a horizontal position and which rely on manual application and removal of the chemicals and liquids used in the developing process.

Referring now to FIGS. 7 and 8, another embodiment of the lithographic plate developing apparatus, generally designated by the numeral 110, is shown wherein the lithographic plate to be developed (not shown) is temporarily but securely mounted to the front plate member 118 which overlies the base 112 in a horizontal attitude (FIG. 7). As with the preferred embodiment described earlier, the front plate member 1118 is provided with a series of special openings or perforations 120 overlying a vacuum chamber 122 mounted on the under surface thereof.

The same spray pipe 24 developing cylinder 26 assembly described above in connection with the preferred embodiment 10 is employed in the embodiment depicted inFlGS. 7 and 8 except that it is adapted to move longitudinally back and forth over the top surface of the front plate member 1 18 in a horizontal path i.e., parallel to the horizontally mounted front plate member 1118. This cyclic movement of the spray pipe 24 developing cylinder 26 assembly again is accomplished by means of a pair of transversely spared, rotatable ball screws 28 and 30 suitably journaled for rotation adjacent each end thereof and threadably supporting the subframe members 32 and 24 of the spray pipe 24 developing cylinder 26 assembly. While not shown, the ball screws 28 and 30 are reversibly driven by the same drive train described above in connection with the preferred embodiment of the present invention, thus causing the spray-pipe 24 developing cylinder 26 assembly to move cyclically in a longitudinal direction over the surface of the exposed lithographic plate being developed. The contact segments 36 of the developing cylinder 26 similarly are indexed and oscillated back and forth in a transverse direction and serve to spread evenly over the surface of the lithographic plate being developed the various chemicals and liquids used in the developing process and which are selectively supplied thereto by the spray pipes-24 in the same manner previously described.

in this second embodiment of the developing apparatus llltl, the excess chemicals and wash water applied during their pre-selected application cycles are caused to flow by the contact segments 36 of the developing cylinder 26 to each end 'of its longitudinal movement over the lithographic plate being developed, where a series of spaced, downwardly angled gutters 1131i lead to a drain trough 182 which is thence drained by sewer (now shown). Thus, again, by completely automated means, the present invention provides for lithographic plate development even a horizontal attitude while obviating the necessity for manual operations to apply the chemicals and liquids used in the developing process or to clean off the excess chemicals and liquids subsequent to their application.

While the present invention has been described with some particularity of a pair of detailed embodiments thereof, it will become readily apparent to those skilled in the art that many variations in the details thereof can be made without departing from its scope. For example, the vacuum means described for holding the lithographic plate during the developing process could as easily be be replaced by mechanical locks, temporary adhesives, magnetic devices, and the like. Similarly, the various drives, while described as fully automated electric motors, fans, etc. could as readily be substituted by a combination of electric, hydraulic or pneumatic devices, all such substitutions being well within the perview of any person skilled in the art.

It would also be within the skill of the art having the benefit of the foregoing disclosure to appreciate that the lithographic plate developing apparatus of the present invention can be adapted as space and requirements dictate to maintain the plate to be developed on the apparatus at any angle with respect to the base ranging from about (horizontal) to about 90 (vertical) without departing from the scope of the invention as defined in the following claims.

What is claimed is:

l. A lithographic plate developing apparatus comprising:

a. a horizontal base,

b. a front plate member mounted on said base,

c. holding means for temporarily but securely mounting a lithographic plate to be developed on said front plate member,

d. developing means spaced from and extending transversely across said front plate member and adapted for longitudinal cyclic movement back and forth over the front plate member in a plane parallel thereto,

1. said developing means including a plurality of applicators for sequentially applying to said lithographic plate being developed the various chemicals and liquids used in the developing process during subsequent cyclic motions of said developing means, and

2. a plurality of contact means for evenly spreading said chemicals and liquids over the surface of the lithograph plate being developed,

a. said plurality of contact means being selectively indexable so as to provide predetermined contact with said lithographic plate by only one of said contact means during any given cycle of said developing means,

e. driving means for imparting said cyclic movement to said developing means, and f. oscillating means for imparting transverse back and forth motion to said contact means. 2. A lithographic plate developing apparatus according to claim 1 wherein said front plate member is mounted on said base at an angle with respect thereto ran ing to about A 1 ographic plate developing apparatus according to claim 1 wherein said front plate member is mounted on said base in a horizontal plane parallel thereto.

4. A lithographic plate developing apparatus according to claim 1 wherein said lithographic plate holding means comprises a vacuum chamber positioned under a plurality of openings provided in said front plate member in an area approximating the area to be occupied by the lithographic plate temporarily but securely mounted thereon.

5. A lithographic plate developing apparatus according to claim 1 wherein said plurality of applicators included within said developing means is comprised of a series of transversely extending tubular members provided with a plurality of longitudinally spaced nozzle openings directed toward thelithographic plate to be developed, each tubular member adapted to supply one of the given chemicals or liquids used in the developing process.

6. A lithographic plate developing apparatus according to claim 1 wherein said plurality of contact means included within said developing means is a cylindrical member comprised of a series of transversely extending, circumferentially spaced contact segments provided with a relatively soft material on the surface adapted to contact said lithographic plate being developed, and each contact segment is selectively placeable into contact with said lithographic plate by indexing means adapted to rotate said cylindrical member through a predetermined angle of rotation.

7. A lithographic plate developing apparatus according to claim l wherein said driving means is comprised of a pair of spaced, parallel ball screws journaled for rotation adjacent each end and overlying said front plate member in a plane parallel thereto, said spaced, parallel ball screws threadably supporting said developing means, and means for imparting reversing rotation to said ball screws.

8. A lithographic plate developing apparatus according to claim 1 wherein said oscillating means is a driven cam wheel-linkage means.

9. A lithographic plate developing apparatus according to claim 1 wherein said developing means includes, in addition, drying means selectively operable to dry said lithographic plate subsequent to completion of the developing cycles of said developing means. 

1. A lithographic plate developing apparatus comprising: a. a horizontal base, b. a front plate member mounted on said base, c. holding means for temporarily but securely mounting a lithographic plate to be developed on said front plate member, d. developing means spaced from and extending transversely across said front plate member and adapted for longitudinal cyclic movement back and forth over the front plate member in a plane parallel thereto,
 1. said developing means including a plurality of applicators for sequentially applying to said lithographic plate being developed the various chemicals and liquids used in the developing process during subsequent cyclic motions of said developing means, and
 2. a plurality of contact means for evenly spreading said chemicals and liquids over the surface of the lithograph plate being developed, a. said plurality of contact means being selectively indexable so as to provide predetermined contact with said lithographic plate by only one of said contact means during any given cycle of said developing means, e. driving means for imparting said cyclic movement to said developing means, and f. oscillating means for imparting transverse back and forth motion to said contact means.
 2. A lithographic plate developing apparatus according to claim 1 wherein said front plate member is mounted on said base at an angle with respect thereto ranging up to about 90*.
 3. A lithographic plate developing apparatus according to claim 1 wherein said front plate member is mounted on said base in a horizontal plane parallel thereto.
 4. A lithographic plate developing apparatus according to claim 1 wherein said lithographic plate holding means comprises a vacuum chamber positioned under a plurality of openings provided in said front plate member in an area appRoximating the area to be occupied by the lithographic plate temporarily but securely mounted thereon.
 5. A lithographic plate developing apparatus according to claim 1 wherein said plurality of applicators included within said developing means is comprised of a series of transversely extending tubular members provided with a plurality of longitudinally spaced nozzle openings directed toward the lithographic plate to be developed, each tubular member adapted to supply one of the given chemicals or liquids used in the developing process.
 6. A lithographic plate developing apparatus according to claim 1 wherein said plurality of contact means included within said developing means is a cylindrical member comprised of a series of transversely extending, circumferentially spaced contact segments provided with a relatively soft material on the surface adapted to contact said lithographic plate being developed, and each contact segment is selectively placeable into contact with said lithographic plate by indexing means adapted to rotate said cylindrical member through a predetermined angle of rotation.
 7. A lithographic plate developing apparatus according to claim 1 wherein said driving means is comprised of a pair of spaced, parallel ball screws journaled for rotation adjacent each end and overlying said front plate member in a plane parallel thereto, said spaced, parallel ball screws threadably supporting said developing means, and means for imparting reversing rotation to said ball screws.
 8. A lithographic plate developing apparatus according to claim 1 wherein said oscillating means is a driven cam wheel-linkage means. 